1. Field of the Invention
The present invention relates to a seat sliding device and in particular to a seat sliding device for use in a motor vehicle.
2. Description of the Related Art
In general, a conventional seat sliding device, as disclosed in Japanese Patent Laid-open Publication No. 62-238136, includes a pair of laterally spaced lower rails both of which are secured to a floor of a vehicle body and a pair of upper rails slidably mounted on the corresponding lower rails. During vehicle collision, a large upward force is applied to the upper rail. In order to prevent separation of each upper rail from the lower rail upon application of such a force, a bent portion is formed on each rail. The bent portions of opposing upper and lower rails are interlocked with each other, thereby preventing separation of the upper rail from the lower rail.
However, if the opposing portions of the upper and lower rail forming the interlocking portion have an insufficient area, the interlocking function may still fail when an unexpected large force is applied to the upper rail, thereby separating the upper rail from the lower rail.